Power Line Communication (PLC) refers to a special communication mode in which voice or data is transmitted using a high-voltage power line (typically at a voltage level of 35 kV or above in the field of a power carrier), a medium-voltage power line (at a voltage level of 10 kV) or a low-voltage distribution line (a subscriber line at 380/220V) as an information transmission medium.
A power-line based wall-plugged communication apparatus, e.g., a power modem, is often used at home to have a terminal device networked. The power modem, also referred to as a power network bridge, is a device which modulates a network signal onto a power line to address the problem of network wiring by means of the existing power line.